Integrated memory control apparatus

ABSTRACT

An integrated memory control apparatus including a first interface decoder, a second interface decoder and an interface controller is provided. Wherein, the first interface decoder is coupled to a control chip through a first serial peripheral interface (SPI), the second interface decoder is coupled to a micro-processor unit through a general transmission interface, and the interface controller is coupled to a memory through a second SPI. When the interface controller receives the request signals from the control chip and the micro-processor unit, the control chip may correctly read data from the memory through the first and second SPI. On the other hand, the micro-processor unit may stop reading data from the memory through the general transmission interface. Therefore, the control chip and the micro-processor unit may share the same memory.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of patent application Ser. No.11/941,983 filed on Nov. 19, 2007, which claims the priority benefit ofTaiwan patent application serial no. 96133220, filed Sep. 6, 2007 and isnow pending. The entirety of each of the above-mentioned patentapplications is hereby incorporated by reference herein and made a partof this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an integrated memory control apparatus.More particularly, the present invention relates to an integrated memorycontrol apparatus for a serial transmission interface.

2. Description of Related Art

Flash memories are commonly used components on main boards of thecomputers, and are widely applied in personal computers and notebookcomputers. Various kinds of data may be stored in the flash memory, andtherefore South Bridge chips and various kinds application specificintegrated circuits (ASICs) disposed on the main board may completespecific instructions by accessing data stored in the flash memory.

FIG. 1 is a block diagram illustrating a part of a conventional mainboard. Referring to FIG. 1, the conventional main board 100 includesflash memories 110 and 120, a South Bridge chip 130 and an ASIC 140. TheASIC 140 includes a micro-processor unit 141 and a memory controller142. The South Bridge chip 130 and the ASIC 140 may respectively accessthe data stored in the flash memories 110 and 120 through the serialperipheral interfaces (SPI) SPI1 and SPI2.

Moreover, the memory controller 142 is used for controlling read andwrite of the flash memory 120. The micro-processor unit 141 is used forwriting the data into the flash memory 120 or reading the data from theflash memory 120 according to an operation of the memory controller 142.During a data transmission, the data transmission between themicro-processor unit 141 and the flash memory 120 is performed via ageneral transmission interface GTI1. Since the memory controller 142 maytransmit a waiting signal to the micro-processor unit 141 through asignal line of the general transmission interface GTI1, themicro-processor unit 141 may timely stop reading of the data from theflash memory 120 in response to the received waiting signal.

However, as to the South Bridge chip 130, the signal line within theserial peripheral interface SPI1 cannot transmit the waiting signal.Therefore, when the South Bridge chip 130 begins to read the data fromthe flash memory 110 by sending a request signal, a wait state cannot bearbitrarily inserted during data reading of the South Bridge chip 130.In other words, the South Bridge chip 130 and the micro-processor unit141 of the ASIC 140 cannot share the same flash memory. In this case,fabrication cost of the conventional main board 100 is greatlyincreased, and a layout area of its printed circuit board will be morecomplicated, and accordingly, it is highly desirable to simplify andimprove the circuit layout of the main board.

SUMMARY OF THE INVENTION

The present invention is directed to an integrated memory controlapparatus used for controlling transmitted signals between a memory anda control chip, and between the memory and a micro-processor unit, suchthat the control chip and the micro-processor unit may share the samememory.

The present invention provides an integrated control apparatus includinga first interface decoder, a second interface decoder and an interfacecontroller. The first interface decoder is coupled to a control chipthrough a first serial peripheral interface (SPI), the second interfacedecoder is coupled to a micro-processor unit through a generaltransmission interface, and the interface controller is coupled to thefirst interface decoder and the second interface decoder, and is coupledto a memory through a second SPI.

It should be noted that the first interface decoder and the secondinterface decoder are respectively used for decoding received signals.Moreover, when the first interface decoder and the second interfacedecoder respectively receive request signals from the control chip andthe micro-processor unit, the second SPI bridges the signal sent fromthe first interface decoder under control of the interface controller,and the second interface decoder may transmit a waiting signal outputfrom the interface controller to the micro-processor unit through thegeneral transmission interface, such that the micro-processor unit maystop sending signals to the second interface decoder, and datatransceiving of the first interface decoder may not be influenced by therequest signals of the micro-processor unit.

In an embodiment of the present invention, a frequency of a clock signalsent from the aforementioned first SPI is smaller than that of thesecond SPI. Further, the frequency of the clock signal sent from thesecond SPI is varied with time, so as to link the transmitted signals ofthe first SPI with that of the second SPI.

Since the first interface decoder and the second interface decoder ofthe present invention are respectively coupled to the generaltransmission interface and the

SPI, and when the interface controller receives the request signals fromthe control chip and the micro-processor unit, the control chip maycorrectly read data from the memory, and the micro-processor unit maystop reading data from the memory. Therefore, the control chip and themicro-processor unit may share the same memory.

In order to make the aforementioned and other objects, features andadvantages of the present invention comprehensible, a preferredembodiment accompanied with figures is described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a part of a conventional mainboard.

FIG. 2 is a diagram illustrating an integrated memory control apparatusaccording to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an integrated memory control apparatushaving a serial peripheral interface structure with a standardspecification.

FIG. 4 is a timing diagram for demonstrating the embodiment of FIG. 3.

DESCRIPTION OF EMBODIMENTS

A main technique feature of the present invention is that two decodersare respectively coupled to a general transmission interface and aserial peripheral interface (SPI), such that an interface controller mayreceive and arbitrate request signals sent from a control chip and amicro-processor unit. In this case, the control chip coupled to theserial peripheral interface and the micro-processor unit may share asame memory. Examples will be set for to describe an integrated memorycontrol apparatus of the present invention. However, these examples arenot intend to limit the scope of the present invention, and it should beunderstood to those skilled in the art that various modifications andvariations can be made to the embodiments of the present inventionwithout departing from the scope or spirit of the present invention.

Before the embodiments of the present invention are described, thememory used for the following description is assumed to be a flashmemory, and the control chip is a South Bridge chip. It should beunderstood by those skilled in the art the memory and control chip of amain board may be renewed along with developing of techniques, andtherefore other kinds of control chips and memories may also be appliedherein.

FIG. 2 is a diagram illustrating an integrated memory control apparatusaccording to an embodiment of the present invention. For convenience, aSouth Bridge chip 210, a micro-processor unit 220 and a flash memory 230are further illustrated in FIG. 2. Referring to FIG.2, the integratedmemory control apparatus 200 includes interface decoders 201 and 202, aninterface controller 203 and a memory unit 204, wherein the interfacecontroller 203 includes an arbiter (not shown). The interface decoder201 is coupled to the South Bridge chip 210 through a serial peripheralinterface SPI21. The interface decoder 202 is coupled to themicro-processor unit 220 through a general transmission interface GTI21.The interface controller 203 is coupled to the interface decoders 201and 202, and is coupled to the flash memory 230 through a serialperipheral interface SPI22. The memory unit 204 is coupled between theinterface decoder 201 and the interface controller 203.

During operation, the interface decoders 201 and 202 are used fordecoding the received signals. Therefore, when the South Bridge chip 210and the micro-processor unit 220 respectively send a request signal forreading data from the flash memory 230, the interface decoders 201 and202 may decode the request signals to a format that the interfacecontroller 203 may interpret. Now, the arbiter in the interfacecontroller 203 may arbitrate the request signals sent from the SouthBridge chip 210 and the micro-processor unit 220. Since the interfacedecoder 201 has a higher priority than that of the interface decoder202, the serial peripheral interface SPI22 may bridge the signal sentfrom the interface decoder 201. Namely, the serial peripheral interfaceSPI22 may bridge the signal sent from the serial peripheral interfaceSPI21.

When the flash memory 230 receives the signals sent from the serialperipheral interface SPI21, the flash memory 230 may transmit the datato be read by the South Bridge chip 210 to the interface controller 203.Next, the interface controller 203 may transmit the data sent from theflash memory 230 to the interface decoder 201. By decoding of theinterface decoder 201, the South Bridge chip 210 may read the data fromthe flash memory 230 through the serial peripheral interface SPI21. Itshould be noted that during data transmission, the interface controller203 may first temporarily store the data sent from the flash memory 230into the memory unit 204, and then transmit the data to the interfacedecoder 201.

On the other hand, the interface controller 203 may send a waitingsignal to the interface decoder 202. The interface decoder 202 thendecodes the waiting signal and transmits the decoded waiting signal tothe micro-processor unit 220 through the general transmission interfaceGTI21. When the micro-processor unit 220 receives the waiting signalfrom the interface controller 203, reading of the data from the flashmemory 230 will be pended, until the interface controller 203 permitsthe request signal sent from the micro-processor unit 220.

It should be noted that when the integrated memory control apparatus 200and the micro-processor unit 220 are simultaneously disposed in anapplication specific integrated circuit (ASIC) 240, the micro-processorunit 220 of the ASIC 240 and the South Bridge chip 210 may share thesame flash memory 230. Therefore, compared to a conventional technique,the main board applying the integrated memory control unit 200 of thepresent invention may integrate the memories within the main board, soas to effectively decrease a fabrication cost and facilitate a circuitlayout.

To further describe the scope of the present invention, the serialperipheral interface with a standard specification is taken as anexample to further describe the integrated memory control apparatus 200.In this case, an embodiment of FIG. 3 is provided along with a timingdiagram of FIG. 4 to demonstrate the transmitted signals of the serialperipheral interfaces SPI21 and SPI22.

Referring to FIG. 3 and FIG. 4, the serial peripheral interface SPI21includes 4 signal lines, respectively used for transmitting a clocksignal CLK21, an enable signal CS21, a master-in-slave-out signal MISO21and a master-out-slave-in signal MOSI21. Similarly, the serialperipheral interface SPI22 also includes 4 signal lines, respectivelyused for transmitting a clock signal CLK22, an enable signal CS22, amaster-in-slave-out signal MISO22 and a master-out-slave-in signalMOSI22.

In addition, a signal ST21 is used for representing a data state of theserial peripheral interface SPI21, and a signal BN21 is used forrepresenting a bit-order of the signal ST21. For example, theaddr2˜addr0 for representing a start address of the data respectivelyhave 8 bits. Moreover, a signal ST22 is used for representing the datastate of the serial peripheral interface SPI22, and a signal BN22 isused for representing the bit-order of the signal ST22.

During operation, when a logic level of the enable signal CS21 is switchfrom a high level to a low level, it represents the South Bridge chip210 is sending a request signal to the flash memory 230. Then, the SouthBridge chip 210 may sequentially generate an instruction inst and thestart addresses addr2˜addr0 of the data. Wherein, the instruction instindicates that the South Bridge chip 210 requests a reading cycle forreading the data from the flash memory 230, and the generated signals bythe South Bridge chip 210 may be transformed into themaster-out-slave-in signal MOSI21 in the serial peripheral interfaceSPI21, so as to transmit the generated signals to the interfacecontroller 203 through the interface decoder 201.

It should be noted that before the interface controller 203 receives therequest signals from the South Bridge chip 210, the arbiter therein maynot be in an idle state.

Namely, the arbiter may have permitted the request signal sent from themicro-processor unit 220, such that the serial peripheral interfaceSPI22 controlled by the interface controller 203 may be bridging theinstruction inst' and the start addresses addr'2˜addr'1 of the data sentfrom the micro-processor unit 220.

However, when the interface controller 203 receives the request signalsent from the South Bridge chip 210 through the interface decoder 201,the arbiter of the interface controller 203 may arbitrate the requestsignals sent from the South Bridge chip 210 and the micro-processor unit220. Since the request signal sent from the South Bridge chip 210 has ahighest priority, the arbiter of the interface controller 203 permitsthe request signal sent from the South Bridge chip 210. Then, as shownby an arrow 401 in FIG. 4, the interface controller 203 may again switchthe logic level of the enable signal CS22, such that the serialperipheral interface SPI22 may bridge the instruction inst and the startaddresses addr2˜addr0 of the data sent from the South Bridge chip 210.In other words, the serial peripheral interface SPI22 is used forbridging the signals sent from the interface decoder 201.

On the other hand, the interface controller 203 may send a waitingsignal to the interface decoder 202. The interface decoder 202 thendecodes the waiting signal and transmits the decoded waiting signal tothe micro-processor unit 220 through the general transmission interfaceGTI21. When the micro-processor unit 220 receives the waiting signalfrom the interface controller 203, reading of the data from the flashmemory 230 performed by the micro-processor unit 220 will be pended.

Furthermore, during data transmission of the serial peripheralinterfaces SPI21 and SPI22, since a frequency of the clock signal CLK21sent from the serial peripheral interface SPI21 is small than thefrequency of the clock signal CLK22 sent from the serial peripheralinterface SPI22, the serial peripheral interfaces SPI21 and SPI22 mayalmost simultaneously complete transmission of the instruction inst andthe start addresses addr2˜addr0 sent from the South Bridge chip 210, asshown of an arrow 402 of FIG. 4. Further, the frequency of the clocksignal CLK22 sent from the serial peripheral interface SPI22 is variedwith time. Therefore, the time points for the serial peripheralinterface SPI22 transmitting the instruction inst and the startaddresses addr2˜addr0 may correspondingly fall behind the time pointsfor the serial peripheral interface SPI21 transmitting the instructioninst and the start addresses addr2˜addr0.

In other words, the interface controller 203 may complete reading of thedata from the flash memory 230 faster than that of the South Bridge chip210, such that the serial peripheral interface SPI22 may correctlyreceive the signals from the serial peripheral interface SPI21.Accordingly, the South Bridge chip 210 may read the data from the flashmemory 230 through the serial peripheral interface SPI21. It should benoted that when the interface controller 203 finishes reading data fromthe flash memory 230, the interface controller 203 may re-arbitrate thereceived request signals so as to permit the request signal sent fromthe micro-processor unit 220.

On the other hand, when the flash memory 230 retains the data rdat to beread by the South Bridge chip 210 according to the received instructioninst and the start addresses addr2˜addr0, the serial peripheralinterface SPI21 may also correctly receive the signals sent from theserial peripheral interface SPI22, and the South Bridge chip 210 mayread the data rdat from the flesh memory 230.

In summary, two interface decoders of the present invention arerespectively coupled to the general transmission interface and theserial peripheral interface. When the interface controller receives therequest signals from the control chip and the micro-processor unit, thecontrol chip may correctly read data from the memory, and themicro-processor unit may stop reading data from the memory according tothe waiting signal. Therefore, the control chip coupled to the serialperipheral interface and the micro-processor unit may share a samememory.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. An integrated memory control method, for an interface controllercoupled to a control chip through a first serial peripheral interface,coupled to a micro-processor unit through a general transmissioninterface, and coupled to a memory through a second serial peripheralinterface to control transmitted signals between the memory and thecontrol chip, and between the memory and the micro-processor unit, theintegrated memory control method comprising: receiving a first requestsent from the control chip and a second request sent from themicro-processor unit respectively for reading data from the memory;bridging the second request to the memory; sending a wait signal to themicro-processor unit; operating a frequency of a first clock signal sentfrom the second serial peripheral interface higher than a frequency of asecond clock signal sent from the first serial peripheral interface; andvarying the frequency of the second clock when time points for thesecond serial peripheral interface transmitting addressescorrespondingly fall behind time points for the first serial peripheralinterface SPI transmitting addresses.
 2. The integrated memory controlmethod as claimed in claim 1, wherein the control chip is a South Bridgechip.
 3. An integrated memory control method, for an interfacecontroller coupled to a control chip through a first serial peripheralinterface, coupled to a micro-processor unit through a generaltransmission interface, and coupled to a memory through a second serialperipheral interface to control transmitted signals between the memoryand the control chip, and between the memory and the micro-processorunit, the integrated memory control method comprising: receiving a firstrequest sent from the control chip and a second request sent from themicro-processor unit respectively for reading data from the memory;bridging the second request to the memory; sending a wait signal to themicro-processor unit; operating a frequency of a first clock signal sentfrom the second serial peripheral interface higher than a frequency of asecond clock signal sent from the first serial peripheral interface;varying the frequency of the second clock when time points for thesecond serial peripheral interface transmitting addressescorrespondingly fall behind time points for the first serial peripheralinterface SPI transmitting addresses; and temporarily storing data sentfrom the memory into a memory unit and then transmitting the data to thecontrol chip.
 4. The integrated memory control method as claimed inclaim 3, wherein the control chip is a South Bridge chip.
 5. Theintegrated memory control method as claimed in claim 3, wherein thememory unit comprises a static random access memory.